The pervaporation performance of EC-HBPE membrane

An aliphatic type of Hyperbranched Polyester (HBPE) was synthesized from 2, 2-dihydroxymethyl propanyl acid (DMPA) and 1, 1, 1-trihydroxymethyl propane (TMP) via Pseudo-One-Step method, and employed to improve the pervaporation properties of Ethyl Cellulose (EC) membrane on Benzene/Cyclohexane separation. The permeate flux of membrane was enhanced greatly with the similar separation factor, when moderate amount of HBPE was added into EC membrane. The sorption properties of EC-HBPE and EC membranes were investigated. The results indicate that, the sorption selectivity of EC membrane dosn't changed significantly, but the sorption amount at equilibrium for EC-HBPE is elevated in the case of the content of G4HBPE in EC is 20% (mass fraction), and all membranes show more preferential toward Benzene than Cyclohexane. The total permeate flux of EC-G4HBPE membrane increases from 14 kg/um·m²·h of EC to 34 kg/um·m²·h, and the separation factor from 3.25 of EC to 3.73 for a binary mixture containing 10% Benzene at 40°C.